Signaling apparatus.



H. SHOEMAKER.

SIGNALING APPARATUS.

APPLICATION man SEPT.29, 1911.

Patented Feb. 8, 1916.

2 SHEETS-SHEfT I .arzzllzmrlllllvla IN l/E N TOR WITNESSES.

H. SHOEMAKER.

SIGNALING APPARATUS.

APPLICATION HLED SEPT.29, 1911.

1,170,853. Patented Feb. 8, 1916.

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

HARRY SHOEMAKER, F JERSEY CITY, NEW JERSEY, ASSIGNOR TO MARCONI WIRE- LESS TELEGRAPH COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

SIGNALING APPARATUS.

Specification of Letters Patent.

Patented Feb. 8, 1916.

Application filed September 29, 1911. Serial No. 651,908.

To all whom it may ooncerri:

Be it known thatI, HARRY SHOEMAKER, a citizen of the United States, residing at Jersey City, county of Hudson, and State of New Jersey, have invented a new and useful Signaling Apparatus, of which the following is a specification.

My invention relates to signaling apparatus, and more particularly to apparatus employed in space signaling such as wireless telegraphy, wireless telephony, and the like, in which electro-radiant energy represents the signals or messages in transmission cases the spark gap is operated under a pressure greater than that of the atmosphere, and in other cases a blast of air is forced across the spark gap continuously during its operation for the purpose of quickly establishing its normal condition.

The function of .the spark gap is well known in the art at the present time and briefly stated, is for the purpose of establishing a good conducting path for the electrical oscillations after the condenser in the oscillating circuit has been charged to a certain critical value. When, however, a number of dischar es take place across the spark gap in rapi succession the intervening air or gases are heated and dissociated in such a manner as to prevent the rapid return to normal conditions. This has been obviated to a certain extent by the above mentioned means; i. c., by inclosing the gap and subjecting it to a greater pressure than that of the atmosphere and also by means of forcing an air blast through the spark gap. In my invention I produce this effect by an entirely new and novel means, i. e., by introducing a solid dielectric in the spark gap immediately aftereach discharge of the condenser, or, in other words, after each spark. With this method it is not necessary to remove the heated or ionized air or to inclose the spark gap and subject it to a pressure, as the insertion of the solid dielectric produces the same effect in a much more constant manner.

For an illustration of some of the forms my invention may take reference is to be had to the accompanying drawings, in which- Figure l is a diagrammatic view of one of the forms which my invention may take,- Flg. 2 is a diagrammatic ,view of a modified form of the same invention, Fig. 3 is a fragmentary view of illustrating the means which I provide for the rotation of the disk which is constructed of a dielectric or nonconducting material; Fig. 4 is a diagrammatic illustration of another modificatioh of my invention; Fig." 5 is a plan view of the rotating disk of dielectric material s owing holes arranged on a circle concentric with the periphery of the disk, and the relative relation of the spark gap and air nozzle is used to produce its rotation; Fig. 6 is'a diagrammatic view of another form which the invention may take.

In Fig. 1, is an alternatinglcurrentgenerator or other suitable source of energy, 21 is a signaling key of circuit breaker, 22 is the primary of the transformer. The generator 20, key 21, and primary 22 are connected in series so that key 21 controls this circuit.

23 is the secondary of the transformer and has its terminals connected to the condenser 13. 12 is an inductance which can be varied by means ofthe contact or clip 15. 11 is a conductor which connects contact 15 and spark gap terminal 10. The spark gap terminal 9 is connected by means of conductor 14 to one of the terminals of the condenser 13, the other terminal of this condenser being connected to the fixed terminal of inductance 12. The axes of spark gap terminals 9 and 10 coincide.- 6 is a disk constructed of a non-conducting or dielectric material such as glass, slate, mica or porcelain. This disk is mounted on the shaft 3 between the collars 4 and 5. The shaft 3 rotates in the bearings l and 2. Around this disk on a Circle concentric with its periphery a number of holes are bored through it. These holes are so situated that their centers successively coincide with the axes of the gap terminals' 9 and 10 when said Iii is rotated. A tube or nozzle 8 is directed-at such an angle to the face of the disk that when air or other gases is forced through-it, it'causes the disk 6 to rotate at a. speed depending nections will hereafter be called the charging circuit.

In Fig. 3, 6 represents a fragment of the disk, 7 one of the holes, and 8 the nozzle for directing the air jet against said disk which causes its rotation. In practice a number of these nozzlesmay be used so arrangedthat at least one or more jets are directed against a hole for any position of the disk. This insures its prompt rotation when the air pressure is turned on. The air used for rotating' this disk may be furnished by any suitable pump, but most conveniently by means of a positive pressure blower or rotary pump givin from two to four pounds pressure and su cient quantity to cause rotation at the proper s d. 9

Referring again to ig. 1, the operation is as follows: The condenser 13 is charged by means of the charging circuit which causes the potential between the spark gap terminals 9 and 10 to rise to such a po nt that it will discharge between said terminals providing one of the holes in the disk lies between said terminals If, however, a solid portion of this disk li,es between the said terminals it will be necessary for the poten-f tial to increase to such a value as to discharge over the surface of said disk. Now, if this disk is in rapid rotation theholes and solid portion of the disk are alternately 1 presentedbetween the spark gap terminals 9 and 10 in sucha manner that the discharge only takes place when said: holes pass between the terminals 9 and 10. The

speed of the disk must be of a proper value to the condenser 13 in order to get a uniform' strength of oscillation in the exciting circuit. If the disk should rotate too slowly the spark would tend to discharge over its. surface and would consequently .be longer and require a greater potential.

If, however, the'mterval of time required.

for the solidportions of the disk to pass between the" terminals 9 and .10 has the proper value the successive charging potentials willbeiuniformaixd. consequently the succexiv'c". Luniform. It will be while the charging circuit -ma'y; ve "a frequency of, say, 60

cycles, that' -iathc 13' will be charged times per second, the number of discharges between the spark gap terminals 9 and 10 may greatly exceed this amount: for instance,.if four holes pass between the spark gap terminals 9 and 10 in 1/120 of a second, there would be four distinct sparks or discharges during this time. This would have the same effect as far as the number of Wave trains radiated per second is concerned as a primary frequency of 240 cycles.- This high spark frequency is of great advantage in wireless telegraphy on account of the more agreeable note produced in the receiving apparatus: but the main advantage to be gained by this invention is the uniform manner in which thesuccessive wave trains are produced, dueto the fact that a solid dielectric is used instead of the more variable gas dielectric as used in presentwireless telegraph systems.

While I have shown a method of rotating the disk by means of air or gas under pressure, any other convenient means can be employed, such as electric motors, either directly connected to the disk or by means of a belt.

. In Fig. 5, 6 represents the disk, 7 the holes through whih the spark passes, 9 shows the position of the spark gap terminals, 8 is the air nozzle for rotating the disk, and 3 is the hole through which the shaft passes.

Fig. 5 taken in connection with Fig. 3

plainly shows the .means for rotating the disk and the relative positionsof the spark gap, air nozzle and holes 'in the disk.

for cperatin two spark gaps in series. In thisfigure t e generator, key and transformer are not shown. 13 is the condenser, I

12 the inductance, 15 the variable contact, 9 and 10 the end spark gap terminals, 24 is the intermediate terminal lying between the two disks 6 and 6, 14 is a conductor connecting spark gap terminal 9 with terminal of condenser 13. The disks 6 and 6 are mounted on the shaft 3 by means of collars 4, 5, 4 and 5'. Shaft 3 is mounted in the bearings 1 and 2, which permit its rotation. 8 is an air nozzle so constructed that it directs a jet of air on both disks 6 and 6'. 25 is a tube connected with the air nozzle 8 and with the air supply pipe. 7

and 7 are holes in the disks which allow the spark to take place when they pass bet ween the terminals 9, 10 and 24. 16 is the radiatand Fig. 2 the ra 'ating circuit and the exformer and with its terminals forms the charging circuit, and is connected to the terminals of condense'rs13 and 13, which are connected in series with reference to the secondary 23. Condensers 13 and 13 are connected in series with the spark gap terminal 10, intermediate terminal 24, spark gap terminal 9. The inductance 12, which may be variable, is connected between the condensers 13 and 13' and to the intermediate terminal 24. This forms two closed oscillating or exciting circuits, the inductance 12- being common to both. The condenser 13, inductance 12, intermediate spark gap terminal 24, spark gap terminal 9, and their connecting conductors, form one of the exciting circuits, condenser 13, spark gap terminal 10,

intermediate spark gap terminal 24, and inductance 12, with their connecting conductors form the other exciting circuit. The disks 6 and 6 are mounted on the shaft 3 by means of collars 4, 5, 4 and 5'. The shaft 3 is mounted in bearings 1 and 2, which permit its rotation. 8 and 25 are air nozzles similar to that shown in Fig. 3. :7 is the holes in the disks. Both these disks have the same number of holes, but the disks are so mounted on the shaft that when the disk 6 has one of its holes presented between and intermediate terminal 24. This allowsfirst the condenser 13 to discharge between the spark gap terminal 9 and intermediate terminal 24 and then the condenser 13 to discharge between spark gap terminal 10 and intermediate terminal 24, thus causing the exciting circuits to operate alternately. The object of this is to enable the use of a greater amount of energy with the same potentials than could be used with a single disk and one exciting circuit. It also permits the production of a greater number of wave trains per second than could be produced with one set of spark ga terminals and one exciting circuit. The ra iating conductor 16, inductance 17, which may be variable, and the ground connection 19, will hereafter be called the radiating circuit, and is in inductive relation with the exciting circuits.

In Fig. 6, 16 is a radiatin conductor, 17 a variable inductance, 9 an 10 are spark gap terminals, and 19 is a ground connection. 6 is a disk of non-conducting material mounted on shaft 3 by means of collars 4 and 5. Shaft 3 is mounted in bearings 1 and 2 to permit its rotation, which can be accomplished by means of an air jet as in Figs. 1, 2 and 4, or by any other convenient means. In this case the exciting circuit and radiating circuit are combined in one and the charging circuit or transformer secondary wouldbe connected to the spark gap terminals 9 and 10. The holes 7 are successively passed between the spark gap terminals 9 and 10 in the same manner as shown in Figs. 1, 2 and 4. With a wireless telegraph system as shown in Fig. 6 this disk is of great value, due to the fact that the capacity of the oscillatingcirouit in this case is extremely small and when the system is charged by a transformer an arc is always produced between terminals 9 and 10, which'practically prevents the production of electrical oscillations in the radiating circuit. Experience has shown that it is almost impossible to produce a great number of wave trains per second with this form of a wireless telegraph transformer, However, with the rotating disk as shown this trouble is prevented and regular and uniform discharges at a high rate can be produced.

While I have shown a number of forms which this invention may take, I do not wish to limit myself to any of the particular forms, and it is to be understood thatthe real departure from the prior art isthe use of a solid dielectric in the spark gap of the wireless telegraph transmitter instead of the fluid dielectric.

- What I therefore claim is:

1. In a wireless telegraph transmitter, the combination of a high frequency oscillatory circuit having discharge terminals separated by a spark gap, and means for presenting alternately a solid dielectric and a fluid dielectric between said terminals for the purpose of regulating the sparking and intermittently clearing the gap of heated gases.

2. In a transmitter of electromagnetic waves, the combination of a high frequency oscillatory circuit having discharge terminals separated by a spark gap, and means for intermittently presenting a solid dielectric between the terminals of said spark gap, for the purpose of regulating the sparking and intermittently clearing the gap of heated gases.

3. In a producer of electro-magnetic waves, the combination of a plurality of sets of terminals separated by spark gaps, means for causing high. frequency disruptive discharges across said gaps, and means for alternately presenting a solid dielectric and a fluid dielectric between the terminals of said spark gaps, for the purpose of regulating the sparking and intermittently clearing the gaps of heated gases.

4. In a transmitter of electromagnetic waves, the combination of a plurality of sets of terminals separated by spark gaps, 13o

means for? causing high frequency disruptive discharges across said gaps, and means for successively presenting a solid dielectric between the terminals of said spark gaps to intermittently clear the gaps of heated gases.

5. In a producerof electro-magnetic waves, the combination of a high frequency oscillatory circuit having terminals separated by a spark gap, a rotary disk of nonconducting material, said disk being so constructed as to present intermittently a solid dielectric between the terminals of the spark gap, and means for rotating said disk, for the purpose of intermittently clearing the 1 gap of heated gases.

6. a producer of electro-magnetic solid dielectrics being presented between the terminals of the several sets in rotation. A

In testimony whereof, I have hereunto affixed my signature in the "presence of the two subscribing witnesses.

HARRY SHOEMAKER.

Witnessesz' J Aims M. SAWYER, WILLIAM H. BOYLE. 

